Recently, with the improvement of people's living standards and significant advancements in digital technologies and optical technologies, cameras are having more and more powerful functions and are available at increasingly lower prices. As a result, a photography trend has developed in which people are getting into the habit of recording their daily lives with cameras.
Generally, a camera lens can be additionally connected with a protective lens for protective purposes, or with neutral density filters (ND filters) or polarizing lenses (polarizers) of various specifications in order to apply the desired photographic effects to the images taken. The aforesaid protective lenses, ND filters, and polarizers (hereinafter collectively referred to as lens elements) are typically designed as individual units, each including a mounting frame and a lens mounted therein, so that a user can mount the lenses of such lens elements to the front side of a camera lens through the mounting frames. However, as each mounting frame and the lens therein form an integral unit and are not designed to be separated from each other with ease, if it is possible at all, the need to carry a plurality of lens elements around presents a problem, simply considering the large storage space required. Moreover, the purchase of a plurality of lens elements is definitely more costly than that of only the lenses therein.
According to the above, the traditional lens elements have large physical volumes, are difficult to carry due to their inseparable mounting frame-and-lens configurations, and incur high purchase costs. These cause huge problems to professional photographers in particular, who are required by profession to carry a lot of photographic equipment with them. Therefore, the issue to be addressed by the present invention is to design a lens element which is more structurally simple, more compact in size, less expensive, and more convenient to use, thereby overcoming the aforesaid drawbacks of the prior art.